Patient therapy which requires use of an indwelling vein access device such as a catheter, ordinarily necessitates patency maintenance of the catheter to permit infusion of medicament, or nutritional solutions as required. Two procedures are typically employed for such patency maintenance.
The so-called SASH procedure includes administration of an anticoagulant heparin solution through a series of steps. Specifically, the indwelling catheter device is first flushed with a bolus dose of saline solution, followed by infusion of a medicament or nutritional solution. The catheter device is again flushed with a bolus dose of saline solution, and the device is thereafter filled with a concentrated solution of heparin. While this procedure is generally regarded as being effective to maintain catheter patency, the procedure can be time-consuming and costly. Additionally, the patient may experience some discomfort and a burning sensation attendant to administration of the heparin.
The second widely employed practice for maintaining catheter patency is generally referred to as the KVO procedure, i.e., keep vein open. This practice entails a substantially continuous infusion of a saline solution at flow rates on the order from about 1 ml per hour (as is typical with power-driven infusion pump devices) to 10 ml per hour (as is typical with gravity systems).
While KVO practice has distinct advantages over the above-described SASH procedure, the required continuous infusion of a saline solution ordinarily severely restricts the mobility of a patient. Gravity flow infusion devices ordinarily require that the patient be positioned in close proximity to an i.v. pole, while infusion pump devices typically are relatively heavy, and require connection to an associated power source.
The present invention relates to a highly portable infusion system which can be employed for KVO practice without restricting patient mobility, and which is further adaptable for infusion of medicament or nutritional solutions as may be required for patient care.